Composite metal hydroxides

ABSTRACT

A COMPOSITE METAL HYDROXIDE EXPRESSED BY THE FOLLOWING COMPOSITION FORMULA:   MGXMY3+(OH)2X+3Y-2Z(A2-)2 AH2O   SUCH COMPOSITE METAL HYDROXIDE HAVING A LAYER CRYSTAL STRUCTURE AND EXHIBITING AN ENDOTHERMAL PEAK OWING TO   ISOLATION OF CRYSTAL WATER AT A TEMPERATURE EXCEEDING 170* C. IN THE DIFFERENTIAL THERMAL ANALYSIS.

SHIGEO MIYATA ET'AL COMPOSITE METAL HYDROXIDES March 12, 1974 3 Sheets-Sheet 2 Filed Dec. 8, 1970 March 12, 1974 SHIGEO MIYATA ETA!- 3,796,792

COMPOSITE METAL HYDROXIDES 3 Sheets-Sheet 5 Filed Dec. 8, 1970 Fig. 4

United States Patent 3,796,792 COIVIPOSITE METAL HYDROXIDES Shigeo Miyata, Teruhiko Kumura, and Minor-u Shimada,

Takamatsu, Japan, assignors to Kyowa Chemical Industry Co., Ltd., Tokyo, Japan Filed Dec. 8, 1970, Ser. No. 96,084 Claims priority, application Japan, Dec. 12, 1969, 44/99,3ss Int. Cl. C01g 56/00, 49/00; C01b 35/00 US. Cl. 423-250 Claims ABSTRACT OF THE DISCLOSURE A composite metal hydroxide expressed by the following composition formula:

such composite metal hydroxide having a layer crystal structure and exhibiting an endothermal peak owing to isolation of crystal water at a temperature exceeding 170 C. in the dilferential thermal analysis.

This invention relates to novel composite metal hydroxides having a layer crystal structure and to process for the preparation of the same.

More specifically, this invention relates to novel composite metal hydroxides having a layer crystal structure and being expressed by the following composition formula:

x 2x+3y-2z 2 a wherein M is a trivalent metal selected from the group consisting of scandium, gallium, yttrium, indium, lanthanum, thallium, titanium, metals of Group V of the Periodic Table, manganese, cobalt, nickel, ruthenium, rhodium, osmium, iridium, rare earth metals and actinide metals; A stands for a divalent inorganic anion; and x, y x and a are positive numbers satisfying the requirements expressed by the following formulas:

and

Compounds of the above-mentioned group of this invention have, in common, a layer crystal structure expressed substantially by the following X-ray dilfraction pattern;

Relative intensity d(A.) (I/I 7.8:32 100 3.91- 1.6 5-80 3.9: 1.6 5-80 2.6:12 5-60 1.54: 0.05 2-10 155110.05 2-10 hydrotalcite (composition formula:

3,796,792 Patented Mar. 12, 1974 pyroaurite (composition formula:

s z(0 )1s s 2 and stichtite (composition formula:

Mgecr 2 16 3 2 have been known, each of which is of natural source. These natural minerals, however, are produced only in very small amounts, and since they contain great quantities of impurities, it is extremely difiicult to recover these minerals in pure form. For such reason, none of these minerals has yet been used for industrial purposes.

The primary object of this invention is to provide a group of novel composite metal hydroxides having a composition diiferent from those of the above-mentioned natural minerals and having a stable layer crystal structure, and a process for the synthesis of these novel composite metal hydroxides.

Another object of this invention is to provide novel composite metal hydroxides having great utility in a broad application range as an intermediate in the production of a magnetic body, an adsorbent, 21 dehydrating agent, a catalyst, an intermediate in the production of a catalyst, at pigment, etc.

This invention will be detailed hereinbelow.

Chemical composition of composite metal hydroxide As the trivalent metal M in the above general Formula I scandium; gallium; yttrium; indium; lanthanum (La); thallium; titanium; metals of Group V of the Periodic Table such as vanadium, antimony and bismuth; manganese; cobalt; nickel; ruthenium; rhodium; osmium; iridium; rare earth metals such as cerium, neodymium (Nd), promethium (Pm), samarium (Sm), europium' (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thullium (Tm), ytterbium (Yb), lutetium (Lu) and didymium which is a mixture of various rare earth metals; and actinide metals such as actium (Ac), thorium (Th), protoactinium (Pa), neptunium (Np), plutonium (Pu), americium (Am), curium (Cm), berkelium (Bk), californium (Cf), einsteinium (E), fermium (Fm), mendelevium (Md), nobelium (No) and a mixture of two or more of these actinide metals may be cited. Particularly preferable trivalent metals are yttrium, indium, scandium, gallium, titanium, vanadium, antimony, bismuth, manganese, cobalt and nickel.

Any divalent inorganic ion may be used as A*. As such inorganic ions oxyacid radicals of sulfur, selenium, tellurium (Te), phosphorus, silicon, germanium, tin, boron, vanadium, chromium, molybdenum, tungsten, manganese, ruthenium (Ru), rhodium, osmium and uranium may be mentioned. Specific examples of such oxyacid radicals are S 0 SO S O SO SeO SeOf, CI'ZOI1=, MOO4=, MO3O7=, SHO3=, MHO4=, UO4=, and UO Halogenic Acid radicals of the above-mentioned metals such as GeF ZrF SiF SnF TiF PtBr and SbF and S=, CO CS and Pt(CN) may also be exemplified. Particularly preferable divalent inorganic ions are C0 CrO Cl'207 B O M005, SeO SeO-f, SiO SO and SO Composite metal hydroxides of above Formula I can possess a layer crystal structure when x, y, z and a satisfy the requirements defined by the above-mentioned inequalities. In composite metal hydroxides of this invention, x, y, z and a stand most preferably for the following numbers:

In this case the composite metal hydroxides are expressed by the following comopsition formula:

It has been found, however, that composite metal hydroxides can have a definite layer crystal structure if x, y z and a are not such positive numbers but they are numbers with certain ranges. Values of x and y may be varied broadly within the range satisfying the requirement of Ax/y8, but in general a good crystal structure is attained within the range of 1.0x/y8. It is particularly preferable that the values of x and y are within the range satisfying 1.2 x/y3.2.

References are made to accompanying drawings for a better illustration of this invention.

FIG. 1 represents a diagram of drawn based on Vegards rule.

FIG. 2 is an X-ray difiraction diagram of FIG. 3 sets forth difierential thermal analysis and thermogravimetric analysis diagrams of FIG. 4 is a diagram illustrating a presumed structure of Mg Bi (CH) (CO -4H O according to this invention.

With reference to, for instance,

the relation between the space distance a'(A.) and the value of x/y is shown by the curve in FIG. 1. From this curve it is seen that the critical point of the composition resides in the point of i.e., Mg/M +=x/y=24, and that when the value of Mg, i.e., x is beyond this point, the space distance becomes relatively large and when M, i.e., y is beyond such point, the space distance d becomes small. This tendency is one of general properties of natural minerals forming a. mixed crystal. Thus it is apparent that composite metal hydroxides of this invention may form a mixed crystal. The determination of the space density d was effected by X-ray diffraction on samples prepared by dropping Mg, M and A each in aqueous medium, and NaOH aque- )llS solution from different burettes while controlling the 9H to 9-12, filtering the reaction product suspension, and Washing and drying the resulting precipitate.

From the above-mentioned facts it is concluded that :rystal lattice points of Mg and M may be replaced :y M and Mg, respectively and that with respect to :ach of Mg, M and A 1 two or more ions may be ntroduced into one crystal lattice point. In general, fornation of a mixed crystal is possible within a range of 4x/y8.

As is seen from the data shown in Table 1, it is gen- :rally necessary that the requirement of TABLE 1 Crystallinity (relative value of Chemical analysis values (molar ratio) ample A -/(Mg+M peak height umber Mg Bi CO; z/ (1+y) at (006) face) 6.0 2 1 1/8 83. l 6. 2 2 0.82 l/10 22. 7 6.0 2 0. 40 1/20 20. 3 6. 2 0. 04 1/200 8. 1 4. 0 2 0. 3 1/20 20. 4 8. 0 2 0. l/ 21. 2

'4 It is generally difliucult to increase the value of over M5. In composite metal hydroxides of this invention it is particularly preferred that the unequality of be satisfied.

As is seen from the data shown in Table 2, within a range forming a mixed crystal, the value of the a/ (x-l-y) is about /2 in most of products. Even in products having a lower crystallinity the value is not smaller than 0.25 and in products having an anion of a larger radius within the said range forming a mixed crystal the value is close to 1. Accordingly, it is essential that the condition of 0.25a/(x+y)l.0 be satisfied. The amount of crystal water was determined by the thermogravimetric analysis, when the data of Table 2 were obtained.

TABLE 2 Crystal M water (y) A (a) /(Hv) B1 CO; 1.3 O. 43 0.5 B1 CO; 2.5 0.50 1.5 B1 CO: 3.4 0.49 2.5 B1 CO: 4.0 0.50 3.0 B1 C0; 3. 8 0.42 3.5 B1 CO; 3.8 0.38 4 Bi CO: 3. 8 0.32 5 Bi CO: 4. 2 0.26 7 Bi CO: 4. 6 0.26 8 2Y B401 7. 0 0. 88 3 2In W04 5. 2 0. 65 3 With reference to values of x, y, z and a of Formula I, individual values of x, z and a can be determined from the above-mentioned inequality formulas by giving a value of 2 to y for conveniences sake.

In suitable composite metal hydroxides of this invention, values of x, y, z and a are as follows:

and

Typical examples of such preferable composite metal hydroxides are shown below:

(a) Composite metal hydroxides having a composition expressed by the formula wherein M is selected from vanadium, antimony and bismuth, and A is selected from CO CrOf, Cr O MO04=, 860 503 804 S103: and B407:-

(b) Composite metal hydroxides having a composition expressed by the formula wherein M is selected from cobalt and nickel, and A is selected from CO CrOf, Cr O MoOf, SeO 803 804 S103: and B407:-

(c) Composite metal hydroxides having a composition expressed by the formula 2-16 2( )7.534 0.5-2.5' 2 wherein A is selected from CO CrOf, Cr O MOO4=, 8604 803 SO4,=, SiO and B407:-

(d) Composite metal hydroxides having a composition expressed by the formula thermal analysis, thermogravimetric analysis and infrared absorption spectrum analysis is construed that the TABLE 3 As described above, the values of the space distance d and relative intensity I/I vary depending on the kinds of M and A and corresponding to the crystallinity. Although the distance at (006) face varies within a range of 3-4 A. but it is possible to easily determine by the abovementioned X-ray difiraction pattern whether a product falls within the scope of this invention or not. More specifically, the distance of each face of (006), (g) and (00%) in Table 3 varies within the above-mentioned range particularly depending on the kind of divalent anion, but changes of other space distances are very small. Accordingly, the determination can be easily made by comparing the pattern of the part where d is not greater than 2.31 A. and confirming the integral-multiplication change of d corresponding to (006), (0012) and '(00l 8 faces. For reference, the X-ray difiraction pattern of is shown in FIG. 2. Further, the determination can be performed based on the data of infra-red absorption spectrum analysis those of Mg In (OH) .-,CO-4H 0 are shown in Table 4) and data of differential thermal analysis (D.T.A.) and thermogravimetric analysis (T.G.A.). Results of differential thermal analysis and thermogravimetric analysis of Mg In (OH) CO -4H O are shown in FIG. 3. The measuring was conducted at a temperature elevating rate of 5 C./min. in air by using LZ-Alg03 as a standard substance.

TABLE 4 Mg In CO Absorbed functional group OH H O Mg-CO 620 111-0 440 The composition of the composite metal hydroxide can be confirmed by the agreement of the value found in the differential thermal analysis and thermogravimetric analysis.

As is seen from FIG. 3, the composite metal hydroxides of this invention exhibit an endothermic peak owing to isolation of crystal water at a temperature higher than substantially 170 C., generally in the range of 200 to 350 C., in the differential thermal analysis. In other words, one of characteristics of the novel composite metal hydroxides of this invention is that the isolation of crystal water is generally caused to occur at high temperatures such as exceeding 200 C.

If an explanation is made by referring to invention are construed to have a structure shown in FIG. 4, though this invention is not limited to that structure Wavelength alone. More specifically, in the novel composite metal hydroxides of this invention, it is presumed that is polymerized by the OH linkage to form an oligomer such as the trimer, M (OH) is polymerized as comonomer with the oligomer, and the divalent anion A is linked with the oligomer of Mg +(OH) whereby the skeleton of the layer structure is formed. Further, water is interposed between the so formed layers and layers are bonded to each other by the hydrogen bond and coordination bond.

It is allowable that a part of the divalent metal Mg is substituted by the trivalent metal M, and it is naturally considered that the amount of crystal water sandwiched in between layers may be varied depending on the ion radius of the divalent anion A The stable crystal structure of the novel substance of this invention will be apparent from the above.

Synthesis of composite metal hydroxide In accordance with this invention, a process is provided for the preparation of composite metal hydroxides having a layer crystal structure and being expressed by the following composition formula:

M is a trivalent metal selected from the group consisting of scandium, gallium, yttrium, indium, lanthanum, thallium, titanium, metals of Group V of the Periodic Table, manganese, cobalt, nickel, ruthenium, rhodium, osmium, indium, rare earth metals and actinide metals; A stands for a divalent inorganic anion; and x, y, z and a are positive numbers satisfying the requirements expressed by the following formulas:

such process comprising reacting (l) x moles of magnesium hydroxide or a compound capable of forming magnesium hydroxide under the reaction conditions and (2) y moles of a hydroxide of the trivalent metal M or a compound capable of forming the hydroxide under the reaction conditions in the presence of at least z moles of the said divalent anion A and water at a pH exceeding 7 and a temperature ranging from 0 to 350 C. under such conditions that the requirement expressed by the formula:

wherein PS stands for the stability constant of Mg(OH) and PS stands for the stability constant of MgA will be satisfied.

In the aqueous or Water-containing organic solvent medium containing Mg M A and OH; the following two react1ons must be considered:

In case the reaction of Formula II occurs predominantly over the reaction of Formula I, the first condition for arriving at the structure of the product of this invention is not satisfied. Accordingly, it is necessary that the reaction conditions must be maintained such that the reaction of Formula I may occur preferentially. These reaction conditions are determined by the difference of the stability constant between the hydroxide Mg(OH) and 7 the metal salt Mg 'A -z The stability constant is defined as follows:

Solubility products (S) of Mg(OH) and Mg +A are expressed as follows:

In this case, the intended product is obtained but its crystallinity is inferior to the crystallinity of the product in 1 In this case, -M +A is coincidentally formed and the intended hydroxide is obtained in an impure form.

In order to prevent the formulation of M +A it is advantageous to conduct the reaction in the presence of OH- in an amount about 2 to about 80 times as large as the amount required for precipitating Mg the hydroxide under the condition of a/ (x+y)%. The competition degree of reactions of Formulas I and II can be contemplated from pS pS =K. Accordingly, optimum conditions for forming and manufacturing the intended AM products can be determined. These conditions are shown in Table 5.

TABLE Continuous process OH feed to (Mg +M Yield Desired optimum for of AM temperature attaining high product Value of K (Mg ++M A feed C.) crystallinity (percent) K g1 Almost equivalent z/(z-l-y) 1/20 Below about 100 Almost 100 equivalent. 1ZK -l ..do 1/20 z/(z+y) 1/8 Below about 60.-.. 5-10 equivalents... ca 100 lgK More than equivalent. l/ z/(z+y) l/8 Below about 30...- 1040 equivalents. 80

Nora-Under the condition of =1 K, formation of the AM product is apparently observed, but in view of the yield and from the economical view point, it is preferred that the reaction is conducted under the conduction of K =1.

When the above stability constants are expressed logarithmically, the following formulas are derived:

logK =logS =pS 1='- 2=P 2 The results of reactions which were conducted under such conditions by employing equivalent amounts of the metal salt and alkali are shown in Table 6.

TABLE 6 Reaction system 1781 PS1 178 -1182 Final reaction product (typical form) Mg, SO42", Sb 10.7 0.7 11.4 MgaSbz(OH)mSO4 4Hzo Mg, M004 Bi 10. 7 O. 1 10. 6 MgeBiz(OH)1eM0O4 41120 Mg, SO3 111 10.7 2.4 8.3 MgeInz(OH)mSOa 4H20 Mg, C03 Bi- 10. 7 5. 0 5. 7 MgsBi2(OH)1aCO3 4H2O Mg 0903 In. 10. 7 6.0 4.7 MgeIng(OH) a(GeOs) 4Hz0 Mg, NH4PO4 Bi=+ 10. 7 l2. 5 1. 8 MgeBi(OH) 6(NH4P04) 4Hz0 plus MgNH4PO4 (trace) In this case, the reaction of Formula 1 advances preferentially, and all the reaction product is the intended product and no by-product is formed.

As the starting compound of the divalent metal Mg to be used in the process of this invention, magnesium hydroxide and compounds capable of forming magnesium hydroxide under the reaction conditions may be cited. Typical examples of such compounds are water-soluble inorganic salts of magnesium such as mineral acid salts, e.g., nitrate, halides and sulfate; carbonate and basic carbonate of magnesium; carboxylates of magnesium such as acetate; and alkoxides of magnesium. -As the starting compound of the trivalent metal M used hydroxides of the trivalent metal M and compounds capable of forming the hydroxides under the reaction conditions may be used. As in the case of magnesium there may be mineral acid salts of the trivalent metal M such as nitrates, halides and sulfates; carbonates and basic carbonates of the trivalent metal M carboxylates of the trivalent metal M such as acetates; and alkoxides of the trivalent metal M may be used. It is also possible to use double 9 salts of hydroxides of trivalent metal M and alkali carbonates.

In accordance with the process of this invention, the above-mentioned starting compounds of magnesium and the above-mentioned starting compounds of the trivalent metal are reacted in the presence of water and of at least z moles of the divalent ion A at a pH exceeding 7.

In case starting compounds of magnesium and/or the trivalent metal M are salts of the divalent ion A 1 it is possible to omit addition of the divalent inorganic ion A Further, it is possible to add the divalent inorganic ion A in the form of an acid or salt, particularly an alkali metal salt, to the reaction system.

The adjustment of the pH may be performed by adding to the reaction system caustic alkali, alkali carbonate, ammonium hydroxide, ammonium carbonate and the like. In this invention, it is generally preferred that the pH is adjusted within the range of from 9 to 12, though the preferable range of the pH varies to some extent depending on the kind of trivalent metal M.

In general, the reaction is conducted in water, but it is possible to conduct the reaction by using as the reaction medium a mixture of water and an organic solvent, for instance, a water-miscible organic solvent such as lower alcohols. The reaction is carried out at temperatures ranging from to 350 0., preferably from 0 to 100 C.

In AM products of this invention, M (OH) is interlocked in the crystal structure in the form of the monomer or oligomer. It is construed that the polymer end of [Mg(OH)2] is made structurally stable by such monomer or oligomer and that two of M (OH) in neighbouring layers may form a hydrogen bond via crystal water, whereby the layer structure is fixed very tightly and stably. The following cases must be considered:

(a) A trivalent metal does not form a hydroxide but a hydroxide halide [M (OH) Hal] or an oxyhalide (M +0Hal), or the hydroxide of the trivalent metal is acidic.

(b) A hydroxide of the trivalent metal absorbs oxygen in the air to form a polyvalent hydroxide, as is shown below:

In order to solve the problem of case (a), it is preferred to add a complex-forming substance such as the abovementioned polyhydric alcohols to thereby prevent formation of by-products. For example, in the case of Bi, BiOCl is formed as a stable by-product.

In order to solve the problem of case (b), it is preferred to conduct the reaction in the above-mentioned nonoxidizing atmosphere.

It is particularly advantageous to conduct the process of this invention by the continuous operation procedures. In this case, aqueous or water-containing alcoholic solutions of Mg M, A- and OH- are prepared separately and used. It is also possible to use a combination of a mixed solution of M and M with a solution of A and a solution of OH- or with a mixed solution of A and OH-.

In supplying these solutions continuously to the reaction vessel, the solutions are introduced to the reaction vessel provided with a stirrer and a temperature controlling device of high accuracy at such feed rates that the abovementionel conditions concerning x and y will be satisfied. As the pH of the reaction liquor greatly influences the quality of the product, it is preferred to control the pH change within a range of 10.5, particularly 510.1. Each solution may be supplied through a conduit or sprayed from the top of the reaction vessel. The reaction is terminated when the amount of the reaction mixture arrives at a certain level, and the reaction mixture is withdrawn from the reaction vessel. If desired, the agitation is conducted at a desired temperature for a certain period of time before the withdrawal of the reaction mixture. The recovered reaction mixture is subjected to the solid-liquid separation. The solid is Washed with water and is dried at a temperature not causing isolation of crystal water, preferably under reduced pressure. It is particularly advantageous to keep the amount of the reaction mixture constant by means of an overflowing device mounted on the reaction vessel. The crystallinity and physical properties of the product are determined almost by the reaction conditions. In order to keep a homogeneous state in the reaction vessel, it is advantageous to mount pH meters on the upper and lower portions of the reaction vessel and select the reaction conditions so that both pH meters indicate the same value.

As the reaction apparatus, a tube recycle system con nected with a centrifugal pump may be adopted. In this case, each solution is fed quantitatively to the suction side of the pump and the pH value is measured just after the extrusion side of the pump to adjust it to a desired value. The amount of the reaction liquor circulated, reaction temperature, the concentrations of starting compounds and the like are suitably arranged, and the reaction mixture in an amount corresponding to the amount of starting solutions fed overflows. The above process is advantageous in that the space of the reaction apparatus is made smaller and the reaction liquor can be agitated vigorously in a small capacity. It is possible to use, instead of a centrifugal pump, an agitator used mainly for the pipe system or other liquid transmitting device. It is preferred that the starting solutions are fed in such amounts that the conditions of x/y=18, especially 2-4, and z/(x+y)=1 /s will be satisfied. With reference to the crystallinity of the product, it is preferable to use A in an amount slightly in excess of the amount required for the formation of the product. Accordingly, it is not absolutely necessary to make the ratio of feed materials strictly in accord with the composition in the product.

The process of this invention may be also conducted batchwise. In this case, various operation procedures such as described below may be adopted.

1) In the same manner as in the continuous process, a mixed solution of Mg and M in the form of watersoluble metals or organic compounds dissolved in organic solvents is charged in a reaction vessel, and a solution of A 1 and OH- (namely an alkali solution) in an amount almost equivalent to the sum of Mg and M is added while stirring. The resulting suspension is post-treated in the same manner as in the continuous process.

(2) A solution of OH- is added to a solution of Mg to convert Mg almost completely to Mg(OH) or both solutions are added to the reaction vessel while maintaining the pH above the level converting Mg almost completely to Mg(OH) The resulting suspension of magnesium hydroxide is blended with solutions of M, A and OH- under agitation.

(3) A solution of OH- is added to an inorganic acidacidified solution of compounds of Mg, M and A under stirring.

(4) A solution of OH- is added to a solution of Mg and A or both solutions are continuously blended while maintaining the pH at a prescribed level. To the resulting mixed liquor a solution of M and a solution of OH are added.

(5) Mg(OH) M +(OH) and A are dissolved in an aqueous medium at elevated temperatures, and a solution of OH- is added to the resulting solution and the reaction is conducted preferably for 05-10 hours.

(6) When starting compounds other than water-soluble metal salts and metal hydroxides are used, the pH and temperature are so selected that these starting compounds may be converted to hydroxides in an aqueous or organic solvent medium, and then the reaction is carried out in the same manner as in (5) above.

In these operations it is also possible to add Mg and M to a solution of OH"- and A The continuous process will now be compared with the batchwise process by referring to typical examples.

The pH is elevated from about 1 to values indicated in Table 7, while gradually adding a solution of CO and OH- dropwise to an aqueous solution of Mg and In in the batchwise procedure. The results are shown in Table 7 where results of the continuous procedure are also shown. In this case, the resulting product is TABLE 7 Crystallinity of product Batchwise Continuous pH of reactlon system reaction reaction TABLE 8 Tempera- Crystal- Bulk density ture C.) linity (mL/ J As is seen from the above results, the crystallinity varies depending on the reaction type and reaction conditions, and at the same pH the continuous process gives better crystallinity than the batchwise process. In the continuous process, the crystallinity and properties of the product vary depending on the pH, and it is observed that difierence in the color tone or the activity against acid is brought about by the change of the pH. By way of example, the relation between the crystallinity and the acid value after the adsorption treatment observed when Mg Bi (-OH) '4H O prepared while varying the pH is used as an adsorbent, is shown in Table 9. The acid value after the adsorption treatment is determined in the following manner:

0.5 g. of the product is added to 100 ml. of dipropylene glycol ether (acid value=0.5) containing dissolved therein acetic acid in an amount corresponding to 500 mg./ liter of KOH, and the mixture is allowed to stand at 50 C. for 3 hours. The filtrate is titrated with alcoholic KOH by using phenol phthalane as an indicator to determine the remaining amount of acetic acid. The acid value is expressed in terms of milligrams of KOH required for neutralizing 1 ml. of the filtrate.

Synthesis of composite metal hydroxide by ion exchange In accordance with this invention, a process is provided for the preparation of composite metal hydroxides having a layer crystal structure and being expressed by the following composition formula:

wherein M is a trivalent metal selected from the group consisting of scandium, gallium, yttrium, indium, lanthanum, thallium titanium, metals of group V of the Periodic Table, manganese, cobalt, nickel, ruthenium, rhodium, osmium, iridium, rare earth metals and actinide metals; A stands for a divalent inorganic anion; and x, y. z and a are positive numbers satisfying the requirements by the following formulas:

and

such process comprising contacting a composite metal hydroxide expressed by the composition formula:

x y 2x+3y=2z( z Z wherein M x, y, z and a are as defined above, and E stands for a divalent inorganic anion other than A with an aqueous solution containing an excess of a salt expressed by the formula Q Q A wherein A is as defined above, Q is selected from alkali metals and ammonium group, and Q is selected from hydrogen atom, alkali metals and ammonium group.

The anion exchange can be easily performed by contacting an aqueous solution containing the divalent inorganic anion to be introduced, in the form of, for instance, a sodium, potassium or ammonium salt, with the starting composite metal hydroxide containing a divalent inorganic anion different from the divalent inorganic anion to be introduced. In case the solution of the divalent inorganic anion to be introduced is too acidic, there is a tendency that the starting composite metal hydroxide is dissolved therein. Accordingly, it is preferred that the contact is conducted under alkaline conditions, especially at a pH exceeding 8. In view of the treatment time, it is preferred that the concentration of the divalent inorganic anion in the solution to be used is at least 0.01 mole per liter. The contact may be effected sufficiently at room temperature but when the contact is conducted at an elevated temperature ranging from 40 to C., the time required for the contact can be generally shortened. Accordingly, it is preferable to conduct the ion exchange at such elevated temperature. In accordance with the above embodiment, at first an Andromedite composite metal hydroxide is formed with use of a divalent anion having a great value of K=pS pS and then an optional divalent anion may be introduced thereinto. This is one of prominent advantages of this invention.

In general, it is preferred that the ion exchange is conducted by a column method, but a solution method may be adopted. By way of example, results of the ion exchange of Mg Bi (OH) CO -4H O with various anions are shown in Table 10.

Post-treatments The product obtained in accordance with the process of this invention is then subjected to hydrothermal treatment and heat aging treatment to hereby increase is crystallinity. The formation of crystals or growth of crystals is promote-d, for instance, by treating an aqueous suspension of the product of this invention or a reaction suspension containing the product of this invention in an autoclave maintained at -350" C. under elevated pressure below 300 atmospheres for 0.5 hour-several days, generally -50 hours. The heat aging treatment is performed by conducting the heating in a similar manner under atmospheric pressure. Although the heat aging treatment cannot increases the crystallinity as well as the hydrothermal treatment, this can be carried out simply without using any specific treatment device.

After such treatments, the product-containing suspension is cooled and filtered. The recovered product is washed and dried according to need. The post-treatments as well as the reaction may be conducted in an inert gas atmosphere so as to prevent oxidation. Additives such as polymerization inhibitors may be used during post-treatments.

By way of example, the change of the crystallinity by the post-treatment of the reaction suspension obtained in the preparation of Mg Bi (OH) 3/2SO -6H O and having the intended product concentration of 150 grams per liter, is shown in Table 11. The crystallinity is expressed in terms of a relative value of the reciprocal number of the half width at (006) face.

TABLE 11 Pressure Crystallinity (atmos- Time (relative Temperature C.) phere) (hours) value) Use In composite metal hydroxides of this invention 2 or more elements are optionally combined in the crystal structure optionally. Accordingly, this invention can provide products meeting various demands. For instance, the composite metal hydroxides of this invention are useful as intermediates in the production of magnetic substances, absorbents, dehydrating agents, divalent anion exchangers, catalysts, intermediates of catalysts, medicines such as antiacids and astringents, excipients and pigmentary cosmetics. The utility of the products of this invention will now be described.

As a method of preparing ferrite, a low temperature homogeneous calcining method utilizing the coprecipitation technique is excellent, but this method involves problems concerning filtration and impurities and has various defects such as non-uniform growth of crystals. On the other hand, since the product of this invention is obtained by the solution reaction conducted at room temperature under atmospheric pressure, it has a structure that can be suitably converted to a highly magnetic spinel structure, Mg +M +-+O Accordingly, the product of this invention is an excellent precursor leading to a highly magnetic substance of a spinel structure. For instance, the product of this invention is converted in a manner shown below by heating at relatively low temperatures:

(wherein MO stands for an oxide of Mg or M) M-ain properties of magnetic substances are determined during the reaction stage. Accordingly, in this point the product of this invention is very advantageous, because the reaction controls can be easily conducted in this invention. Further, the product of this invention is excellent in filterability when compared with conventional hydroxides and is also excellent in that impurities, particularly alkali metals, are hardly incorporated in the product of this invention.

As the product of this invention is a solid which is basic, it can be utilized for adsorption of acidic substances. In the product of this invention, the elution of metals is much lower and the adsorption efiiciency is much higher than in the conventional-adsorbents. Further, the adsorption eificiency and selectivity can be optionally changed by changing the kinds and composition ratios of metals.

Further, the adsorbent property may be changed by varying the kind of anion. Even if crystal water once interposed between layers has been isolated in the product of this invention, when water is given added thereto, crystal water is formed again in the original position of the crystal structure. In other words, the product of this invention has a substantially complete adsorbent capacity and possess characteristics of a solid base and dehydrating agent coincidentally in on crystal structure. Accordingly, the product of this invention is an adsorbent of great utility which can adsorb an acid and water at the same time.

In order to confirm the reversibility of crystal water, T.G.A. measurement was conducted on Sample (A) obtained by drying Mg Bi (OH) CrO -4H O, at 105 C. for 3 hours, Sample (B) obtained by calcining sample (A) at 350 C. for 1 hour and Sample (C) obtained by suspending sample (B) in water and drying the same. The results are as follows:

Crystal water content, Percent 1 1 Calculated value: 7.4%

The results of X-ray dilfraction measurement are as follows:

X-ray diffraction intensity Sample A 26.4 Sample B 6.9 Sample C 26.3

1 Diffraction peak height at (006) face.

As shown above, the product of this invention has a reversibility in absorption and isolation of crystal water, and it is therefore utilized as a dehydrating agent. Accordingly, the product of this invention can separate water from an azeotropic mixture of water and an alcohol, the separation of which is impossible by distillation. The product of this invention can absorb hydrogen as well, but it hardly absorbs alcohols such as ethanol, methanol and ethylene glycol, and acetone.

In the product of this invention, the anion can be easily replaced by other divalent anion. Accordingly, the product of this invention can be used as an ion exchanger.

In view of the composition of the product of this invention, its use as a catalyst is expected. Further, it is sometimes useful as an intermediate leading to the preparation of a catalyst. In the case of catalysts prepared by the co-precipitation method, it is considered that each atom is easily coagulated and the atom arrangement is of poor regularily. Accordingly, the distribution of catalytic points is irregular and the catalytic activity is not uniform. Further, as coagulation of atoms is present in such catalyst, there is a fear that it is easily deactivated. On the other hand, as the precipitate of the product of this invenion has a crystal structure, coagulation of atoms is diflicultly caused to occur and all the atoms are arranged regularly with little disorder. When measured according to X-ray diffraction analysis or from a microscopic photograph, the layer of the crystal structure of the product of this invention is usually found to have a thickness of less than A. Accordingly, it is construed that inthe product of this invention crystal layers grow very thinly. Therefore, when the product of this invention is calcined at temperatures within a certain range, it takes a particulate form in which each atom is in the amorphous state. Thus, the activity is uniform and selective, and a catalyst can be obtained which is hardly degraded by catalyst poison. Further, activities as solid base and specific oxidation and reduction activities can be obtained by suitably selecting a combination of metal and anion. With reference to composite metal hydroxides containing bismuth, vanadium, cobalt or nickel as the trivalent metal M and CO CrO Cr O B O MoO SeO or WO as the divalent inorganic ion A use as catalysts for oxidation of olefins, ammoxidation of olefins, cracking of petroleum hydrocarbons, alkylation of aromatic compounds and the like is expected.

It is another interesting feature of composite metal hydroxides of this invention that the stability against heat may be varied within a range of about 100 C. by changing the kind of anion. Accordingly, it is possible to change optionally change the maximum activity temperature.

As the product of this invention can contain metals such as magnesium and bismuth, it is useful as a medicine. For instance, Mg-Bi type composite hydroxides are promising as anti-ulcer agents. Further, the composite metal hydroxides of this invention are characterized in that incorporation of a monovalent cation such as Na+ of K''' is extremely small.

In the product of this invention, thin layer crystals are meratcd in the petal-like or plane plate-like form. Accordingly, when pressure is imposed on the product of this invention, particles are easily combined with one another by bonding ability between layers. Because of this property, the product of this invention is useful as an excipient excellent in tablet-forming property. The hardness of the MgBiCO type product at various compression pressures is measured by a strong cobb hardness meter and is compared with those of conventional excipients. Results are shown in Table 12.

TABLE 12 Product Alumina. crystallized Compression of this g pressure (kgJcmfi) invention hydroxide Lactose Cellulose The product of this invention can also be used as a pigment. Further, when Co, Ni, CrO Cr O or the like is combined in the crystal structure, these components exhibit a certain refractive index (about 1.5) and form fine particles. Accordingly, such product can be used as a transparent or semitransparent pigment by adding it to resins or other materials to be colored. Still further, the product of this invention has a smooth touch and a good luster, and it is useful as a luster-imparting agent and a sizing agent for paper-manufacturing. As the product of this invention has a layer crystal structure, it exhibits a lustrous oily feeling and is uniform in particle size. In addition, the product of this invention is extremely excellent in weatherability, and particularly at room temperature or temperatures below 100 C. it is highly resistant against water and has a suitable moisture-absorbing property. Still further, it exhibits a good affinity or compatibility with organic-substances. Accordingly, it is useful as a substrate of a paste-like or powdery cosmetic.

EXAMPLE 1 A 500-ml. capacity beaker equipped with a pH electrode was charged with water in an amount sufficient to immerse the pH electrode therein, and an acidic liquor or 9.1 g. of SbC1 and 24.4 g. of MgCl -6H O dissolved in 200 ml. of water and an alkaline liquor of 2.9 g. of Na SO and 12.8 g. of NaOH dissolved in 200 ml. of water were added dro-pwise to the beaker at room temperature and atmospheric pressure under agitation by a mini-stirrer while the amounts of both liquors fed were so adjusted that the pH of the system would be maintained at 10.0-11.0. After completion of the reaction, water was removed from resulting precipitates by means of a dehydrating device equipped vvith a vacuum pump. The precipitates were washed with 200 ml. of Water and dried in the air at C. for 10 hours. The reaction and the after-treatment were conducted in the air decarbonated with concentrated KOH aqueous solution. The decarbonated water was used throughout the process. X-ray diffraction analysis results, chemical analysis values and the composition formula derived therefrom of the product are as follows:

Composition formula Mg Sb (OH)1sSO -4H O:

X-ray diffraction:

1. Analysis values wer measured according to fluorescent X-ray analysis method, chelate titrating method and ordinary chemical analysis method.

2. Parenthesized values in Chemical Analysis indicate molar ratios.

3. d(A) stands for the space distance determined by X-ray dilfraction and I/Io stands for the intensity ratio expressed in the relative value based on the peak heights measured by X- ray diffraction method.

These matters Wlll apply 1n a s1rn1lar manner to subsequent examples.

EXAMPLE 2 A liquor of 9.1 g. of SbCl and 24.4 g. of MgCl -6H O dissolved in 200 ml. of water and a liquor of 2.1 g. of Na CO and 12.8 g. of NaOH dissolved in 200 ml. of water were added dropwise to a 500-ml. capacity beaker charged with ml. of water at room temperature under agitation. The feed rate of each liquor was adjusted so that the pH of the reaction suspension was maintained at 10.01l.0. After completion of the reaction, the resulting suspension was dehydrated by a dehydrating device equipped with a vacuum pump, and the residue was washed with 200 ml. of water and dried at 80 C. for 10 hours. Results of the analysis of the product are as follows:

Composition formula Mg Sb (OH) CO '4H O:

X-ray diffraction:

d(A.) I/I 749 100 3.86 41 Chemical analysis:

MgO 30.2% (6.00)

Sb O 36.5% (1.0)

EXAMPLE 3 A mixed liquor of 50 ml. of a hydrochloric acid-acidified bismuth solution containing 0.4 moles per liter of Bi O 50 ml. of a zinc chloride solution containing 2.4 moles per liter of ZnO and 100 ml. of a liquor of 3.6 g. of mannitol dissolved in water, and another mixed liquor of 25.6 ml. of a sodium. carbonate solution containing 0.785 mole per liter of Na CO and 200 n11. of a caustic soda solution containing 2.0 mole per liter of NaOH were added under agitation at a temperature maintained at 5 C. into a 500-ml. capacity beaker charged with 100 ml. of water. The reaction was carried out while the pH of the reaction suspension was maintained at 1l.0-12.0. The resulting precipitate was treated in the same manner as in Example 2. Results of the analysis of the product are as follows:

Composition formula Mg Bi (OH) CO '4H O:

K =5 .7 x/y =3 z/ (x+y) 1/ 8 X-ray diffraction:

d(A.) I/I 7.49 100 3.70 4 2.58 20 2.37 3 1.52 8

Chemical analysis:

MgO 25.3% (6.04) Bi- O 48.4% (1.0) 4.5% (0.98) H O 22.4% (12.00)

EXAMPLE 4 A liquor of 8.8 g. of InCl and 24.4 g. of

MgCl -6H O dissolved in 200 ml. of water and a liquor of 2.1 g. of Na CO dissolved in 100 ml. of water were added, together with an aqueous solution containing 3.0 moles per liter of NaOH, dropwise at room temperature under agitation into a 500-ml. capacity beaker charged with 100 ml. of water. The addition of the NaOH aqueous solution was adjusted so that the pH of the reaction suspension was maintained above 12.0. After completion of the reaction, the resulting suspension was post-treated in the same manner as in Example 2. Results of the analysis of the product are as follows:

Composition formula Mg In (OH) CO -4H O:

X-ray diffraction:

EXAMPLE A liter capacity beaker was charged with a liquor of 2.1 g. of Na CO and 150 g. of NaOH dissolved in 300 ml. of water, and then a liquor of 13.2 g. of YCl -6H O and 24.4 g. of MgCl -6H O dissolved in 300 ml. of water was added dropwise to the content of the beaker at room temperature under agitation. Since Y is not easily formed into Y(OH) completely in the presence of an equivalent amount of OH-, in this example it was necessary that the OH- ions be present at high concentrations and in amounts of about 10 equivalents. After completion of the reaction, the resulting suspension was transferred to an autoclave and heat-treated at 150 C. for hours. Then it was cooled to room temperature and treated in the same manner as in Example 1. Results of the analysis of the product are as follows:

Composition formula Mg Y (OH) CO -4H O:

X-ray diffraction:

EXAMPLE 6 An aqueous solution of 4.8 g. of NaOH in 50 ml. of water was added to a liquor of 11.3 g. of CoSO -7H O dissolved in ml. of water to form Co(OH) Then the mixed liquor was agitated for 3 days while passing air thereinto, to thereby oxidize Co(OH) by oxygen in the air to Co(OH) The resulting suspension was charged into a 500-ml. capacity beaker, and a liquor of 24.4 g. of MgCl -6H 0 dissolved in 200 ml. of water and a liquor of 2.1 g. of Na CO and 9.6 g. of NaOH dissolved in 100 ml. of water were added dropwise thereto at room temperature under agitation. The resulting reaction suspension was transferred to an autoclave and heat-treated at C. for 15 hours. Then it was cooled to room temperature and post-treated in the same manner as in Example 1. Results of the analysis of the product are as follows:

Composition formula Mg CO (OH) CO -4H O:

X-ray diffraction:

EXAMPLE 7 A liquor of 3.2 g. of VCl and 24.5 g. of MgCl -6H O dissolved in 200 ml. of water and a liquor of 2.1 g. of Na C0 and 13.0 g. of NaOH dissolved in 100 ml. of water were added dropwise in a N gas current to a 500- ml. capacity four-neck flask charged with 100 ml. of degasified ion-exchange water. The addition of both liquors were so adjusted that the pH was maintained at 10.0-11.0. After completion of the reaction, the resulting suspension was dehydrated in a N gas atmosphere. The

remaining solid was dried in a N gas current, washed with 100 ml. of degasified ion-exchange water, and dried at 60 C. for 15 hours in a N gas current. Results of the analysis of the product are as follows:

A liquor of 17.5 g. of Nd(NO -6H O and 24.4 g. of MgC1 -6H 'O' dissolved in 200 ml. of water and a liquor of 2.1 g. of Na CO and 12.8 g. of NaOH dissolved in 200 ml. of water were added dropwise to a 500-ml. capacity beaker charged with 60 ml. of water at room temperature under agitation. The addition was conducted so that the pH was maintained at 100-110, and the reaction was carried out in a N gas atmosphere; After completion of the reaction, the resulting suspension was treated in the same manner as in Example 2. Results of the analysis of the product are as follows:

Composition formula Mg Nd (OH) CO -4H O:

X-ray diffraction:

EXAMPLE 9 40 ml. of an aqueous solution containing 34 mg. of imericium nitrate and 49 mg. of MgCl -6H O and a iolution of mg. of Na CO in 10 m1. of water were added dropwise to a 100-ml. capacity beaker charged with 20 m1. of water at room temperature under agitation. The pH of the reaction liquor was adjusted to 10.0- 11.5 by addition of 0.1 N NaOH aqueous solution. After :ompletion of the reaction, the resulting suspension was .reated in the same manner as in Example 2. Results of X-ray diffraction analysis are as follows:

Composition formula Mg Am (OH) CO 4H O:

C-ray diffraction:

1(A.) I/I 8.66 100 3.97 47 2.61 17 2.35 9 1.55 6 1.51 6

EXAMPLE 10 A liquor of 9.1 g. of SbCl and 24.4 g. of MgCl -6H O issolved in 200 ml. of water and a liquor of 3.6 g. of Ja CrO and 12.8 g. of NaOH dissolved in 200 ml. of

water were added dropwise to a 500-ml. capacity beaker charged with ml. of water at room temperature under agitation. The feed rate of each liquor was adjusted so that the pH of the reaction suspension was maintained at 100-110 After completion of the reaction, the resulting suspension was post-treated in the same manner as in Example 1. Results of the analysis of the product are as follows:

Composition formula Mg Sb (OI-I) CrO 4H O:

X-ray diffraction:

d(A.) I/I 7.49 100 Chemical analysis:

MgO 28.0% (6.02) Sb O 33.7% (1.0) CrO; 13.4% (1.00) H O 25.0% (12.00)

EXAMPLE 11 A liquor of 9.1 g. of SbCl and 24.4 g. of MgCl -6H O dissolved in 200 ml. of water and a liquor of 2.5 g. of Na SO and 12.8 g. of NaOH dissolved in 200 ml. of Water were added, dropwise into a 500-ml. capacity beaker charged with 100 ml. of water at room temperature under agitation. The addition of each liquor was adjusted so that the pH of the reaction suspension was maintained at 10.0-11.0. After completion of the reaction, the resulting suspension was treated in the same manner as in Example 1. Results of the analysis of the product are as follows:

Composition formula Mg Sb OH) 50 4H O:

K 8.3 x/y=3 Z/ (x+y) 1/ 8 EXAMPLE 12 A liquor of 9.1 g. of SbCl and 24.4 g. of MgCl -6H O dissolved in 200 ml. of water and a liquor of 4.7 g. of K MoO and 12.8 g. of NaOH dissolved in 200 ml. of Water were added dropwise to a 500-ml. capacity beaker charged wtih 100 ml. of water at room temperature under agitation. The addition was conducted so that the pH was maintained at 10.0-11.0. After completion of the reaction, the resulting suspension was treated in the same manner as in Example 1. Results of the analysis of the product are as follows:

Composition formula Mg Sb (0H) MoO 4H O:

K: 10.6 x/y=3 z/ (x+ y) 1/ 8 A liquor of 9.1 g. of SbCl and 24.4 g. of MgC1 -6H O dissolved in 2-00 ml. of water, and a liquor of 3.5 g. of K HPO and 12.8 g. of NaOH dissolved in 200 ml. of water were added dropwise to a 500-ml. capacity beaker charged with 100 ml. of water at room temperature under agitation. The addition of both liquors was adjusted so that the pH of the reaction suspension was maintained at 10.0-11.0. The resulting suspension was treated in the same manner as in Example 1. Results of the analysis of the product are as follows:

Composition formula 'Mg Sb (OH)1eHPO -4H O:

16:6.5 .x/y.- 3 z/ (x-l-y) 1/ 8 X-ray difiraction:

EXAMPLE 14 A liquor of 9.1 g. of |SbCl and 24.4 g. of MgCl -6H O dissolved in 200 ml. of water and a liquor of 4.4 g. of K SeO and 12.8 g. of NaOH dissolved in 200 ml. of water were added dropwise to a 500-ml. capacity beaker charged with 100 ml. of water at room temperature under agitation. The addition of both liquors were so adjusted that the pH was maintained at 10.0-11.0. After completion of the reaction, the resulting suspension was treated in the same manner as in Example 1. Results of the analysis of the product are as follows:

Composition formula Mg Sb (OH) SeO 4H O:

EXAMPLE 15 A liquor of 21.0 g. of Ti (SO -8H O and 27.4 g. of MgSO -6H O dissolved in 200 ml. of dilute hydrochloric acid and an aqueous solution containing 2.0 moles per liter of NaOH were added dropwise into a four-neck 22 flask charged with ml. of water. The reaction was conducted by passing N gas through the reaction system so as to prevent the presence of oxygen in the dash and CO in the air. The reaction mixture was agitated at room temperature and the pH thereof was maintained above 11.0 by adjusting the addition of the NaOH aqueous solution. After completion of the reaction, the resulting suspension was rapidly filtered under reduced pressure in a N gas atmosphere, and the recovered solid was dried at about 60 C. for 8 hours in a N gas current, washed under reduced pressure with pure water, and dried under the same conditions as above. Results of the analysis of the product are as follows:

Composition formula Mg Ti (OH) SO -4H O:

LEXAMPLB 16 A liquor of 17.5 g. of Nd(NO -6H O and 24.4 g. of MgCl -6H O dissolved in 200 ml. of water and a liquor of 3.6 g. of Na CrO and 12.8 g. of NaOH dissolved in 200 ml. of water were added dropwise to a 500-ml. capacity beaker charged with 60 ml. of water at room temperature under agitation. The addition was conducted so that the pH was maintained at 10.0-11.0, and the reaction was carried out in a N gas atmosphere. In each liquor, pure water Was used. After completion. of the reaction, the resulting suspension was hydrothermally treated in an autoclave at C. for 12 hours. Then, it was washed with 200 ml. of water and dried at 70 C. for 10 hours in a N gas current. Results of the analysis of the product are as follows:

Composition formula Mg Nd (OH) CrO -4H;,O:

A liquor of 15.0 g. of LaCl -7H 0 and 27.4 g. of MgSO -6H O dissolved in 200 ml. of water and an aqueous solution containing 2.0 moles per liter of NaOH were added dropwise into a four-neck flask charged with 100 ml. of ion-exchange water. The addition of the NaOH aqueous solution was adjusted so that the pH of the reaction suspension was maintained at 7.0-8.0. The reaction was conducted at room temperature under agitation by passing N gas through the flask. After completion of the 23 reaction, the resulting suspension was transferred to an autoclave and subjected to hydrothermal treatment at 150 C. for hours. Then it was cooled, washed with 200 ml. of ion-exchange water and dried at 60 C. for 10 hours in N gas. Results of the analysis of the product are as follows:

Composition formula Mg La (OH) SO -4H O:

X-ray dilfraction:

Chemical analysis:

MgO 27.5% (6.00) La O 37.1% (1.00) 80. 10.9% (1.00) H O 24.6% (12.00)

EXAMPLE 18 A liquor of 3.2 g. of V01 and 24.5 g. of MgCl -6H O dissolved in 200 ml. of Water and a liquor of 3.6 g. of Na CrO and 13.0 g. of NaOH dissolved in 100 m1. of water were added dropwise in a N gas current to a 500 ml. capacity four-neck flask charged with 100 ml. of degasified ion-exchange water. The addition of both liquors were so adjusted that the pH was maintained at 10.0-11.0. After completion of the reaction, the resulting suspension was dehydrated in a N gas atmosphere. The remaining solid was dried in a N gas current at 60 C., Washed with 100 ml. of degasified ion-exchange water, and dried at 60 C. for hours in a N gas current. Results of the analysis of the product are as follows:

Composition formula Mg V (OH) CrO -4H O EXAMPLE 19 A liquor of 15.0 g. of CeCl -7H O, 3.0 g. of NH Cl and 24.4 g. of MgCl -6H O dissolved in 200 ml. of water and a liquor of 2.5 g. of Na SO and 13 g. of NaOH dis- ;olved in 200 ml. of water were added dropwise to a four-neck flask charged with 100 m1. of water in a N gas atmosphere. The addition of both liquors was adusted so that the pH of the reaction suspension was maintained above 11.0. Water was removed from the resulting mspension in a N gas atmosphere and the residue was dried. The solid was washed with water and dried again in a N gas atmosphere at 60 C. for 15 hours. In this 2'4 example pure water was used. Results of the analysis of the product are as follows: Composition formula Mg Ce (OH)1 O '4I-I O:

X-ray diffraction:

EXAMPLE 20 100 ml. of a rhodium chloride solution of a concentration of 0.2 mole/liter calculated as Rhgos were mixed with 100 m1. of a magnesium chloride solution of a concentration of 1.2 moles/liter calculated as MgO. T0- gether with the so formed mixed liquor, a mixed liquor of 25.6 ml. of a Na SO solution of a concentration of 0.8 mole/liter and m1. of a potassium hydroxide solution of a concentration of 4 moles/ liter were added dropwise to a 500-ml. capacity beaker charged with 80 ml. of pure water under agitation. The reaction temperature was maintained at 810 C. and the pH of the reaction liquor was maintained at 10-11. Water was rapidly removed from the resulting suspension, and the remaining solid was washed with 200 ml. of pure water and dried at 60 C. for 15 hours. The reaction was conducted in a N gas atmosphere and pure water was used throughout the example. Results of the analysis of the product are as follows:

Composition formula Mg Rh (OH) SO -4H 0:

EXAMPLE 21 A mixed liquor of 50 ml. of a hydrochloric acid-acidified bismuth solution containing 0.4 mole per liter of Bi O 50 m1. of a magnesium chloride solution containing 2.4 moles per liter of MgO and ml. of an aqueous solution of 3.6 g. of mannitol, and another mixed liquor of 25.6 ml. of a Na SO solution of a concentration of 0.785 mole per liter and 200 ml. of a caustic soda solution containing 2.0 moles per liter of NaOH were added at 50 C. under agitation dropwise to a 50-ml. capacity beaker charged with 100 ml. of water. The reaction was conducted while maintaining the pH of the reaction liquor at 11.012.0. The resulting suspension 25 was treated in the same manner as in Example 1. Results of the analysis of the product are as follows:

Composition formula Mg Bi (H) SO -4H 0:

Chemical analysis:

Bi o 46.6% (1.00) S0 7.8% (0.98) H O 21.6% (12.00)

EXAMPLE 22 A mixed liquor of 50 ml. of a hydrochloric acid-acidified bismuth solution containing 0.4 mole per liter of Bi O 50 ml. of a magnesium chloride solution containing 2.4 moles per liter of MgO and 100 ml. of an aqueous solution of 3.6 g. of mannitol, and another mixed liquor of 25.6 ml. of K CrO solution of a concentration of 0.785 mole per liter and 200 ml. of a caustic soda solution containing 2.0 moles per liter of NaOH were added at 50 C. under agitation dropwise to a 500-ml. capacity beaker charged with 100 ml. of water. The reaction was conducted while maintaining the pH of the reaction liquor at 11.012.0. The resulting suspension was treated in the same manner as in Example 1. Results of the anal- EXAMPLE 23 A mixed liquor of 50 ml. of a hydrochloric acid-acidified bismuth solution containing 0.4 mole per liter of Bi O 50 m1. of a magnesium chloride solution containing 2.4 moles per liter of MgO and 100 ml. of an aqueous solution of 4.0 g. of mannitol, and another mixed liquor of 25.6 ml. of Na SO solution of a concentration of 0.785 mole per liter and 200 ml. of a caustic soda solution containing 2.0 moles per liter of NaOH were added at 50 C. under agitation dropwise to a 500-ml. capacity beaker charged with 100 ml. of water. The reaction was conducted while maintaining the pH of the reaction liquor at 11.0-12.0. The resulting suspension was treated in the same manner as in Example 1. Results of the analysis of the product are as follows:

Composition formula Mg Bi OH) 1650 4H O:

K 1 1.4 x/y=3 z/ (x+y =1/s X-ray diffraction:

d(A.) I/Io 7.60 3.83 60 2.58 32 2.37 28 1.52 20 Chemical analysis:

23.9% (6.04) Bi O 45.7% (1.00) 80.; 9.2% (0.98) H O 21.3% (12.05)

EXAMPLE 24 A mixed liquor of 50 ml. of a hydrochloric acid-acidified bismuth solution containing 0.4 mole per liter of Bi O 50 ml. of a magnesium chloride solution containing 2.4 moles per liter of Mg and 100 ml. of a liquor of 3.6 g. of mannitol dissolved in water, and another mixed liquor of 25.6 ml. of a Na S O solution containing 0.785 mole per liter of Na S O and 200 ml. of a caustic soda solution containing 2.0 moles per liter of NaOH were added under agitation at a temperature maintained at 5 C. into a SOD-ml. capacity beaker charged with 100 ml. of water. The reaction was carried out while the pH of the reaction suspension was maintained at 11.012.0. The resulting precipitate was treated in the same manner as in Example 1. Results of the analysis of the product are as follows:

Composition formula Mg Bi (OH) S O -4H O:

EXAMPLE 25 A mixed liquor of 50 ml. of a hydrochloric acid-acidified bismuth solution containing 0.4 mole per liter of Bi O 50 ml. of a magnesium chloride solution containing 2.4 moles per liter of MgO and 100 ml. of a liquor of 3.6 g. of mannitol dissolved in water, and another mixed liquor of 25.6 ml. of a Na l-IP0 solution containing 0.785 mole per liter of Nag-IP0 and 200 ml. of a caustic soda solution containing 2.0 moles per liter of NaOH were added under agitation at a temperature maintained at 5 C. into a 500-ml. capacity beaker charged with 100 ml. of water. The reaction was carried out while the pH of the reaction suspension was maintained at 11.0-12.0. The resulting precipitate was treated in the same manner as in Example 1. Results of the analysis of the product are as follows:

Composition formula Mg Bi (OH) HPO -4H O:

27 Chemical analysis:

MgO 23.9% (6.07) Bi O 45.6% (1.00) 'HPO 9.2% 0.98) H O 21.2% (12.04)

EXAMPLE 26 A liquor of 21.0 g. of Ti (SO -8H O and 24.4 g. of MgCl -6H O dissolved in 200 ml. of dilute hydrochloric acid and an aqueous solution containing 2.0 moles per liter of NaOH were added dropwise into a four-neck flask charged with a liquor of 2.1 g. of Na CO dissolved in 100 ml. of water. The reaction was conducted at room temperature under agitation by passing a N gas through the flask to prevent oxygen in the air from being present in the flask and controlling the addition of the NaOH aqueous solution so that the pH of the reaction liquor was maintained above 11.0. After completion of the reaction the resulting suspension was rapidly filtered under reduced pressure in a N gas atmosphere, and the residue was dried at about 60 C. for 8 hours in a N gas current, washed with 200 ml. of water under reduced pressure and dried again under the same conditions as above. Results of the analysis of the product are as follows:

Composition formula Mg Ti (OH) CO 4H O:

Chemical analysis:

MgO 37.6% (5.90) Ti O 22.8% (1.00) CO 6.2% (0.89) H O 34.3% (12.00)

EXAMPLE 27 A liquor of 15.0 g. of CeCl -7H O, 3.0 g. of NH Cl and 24.4 g. of MgCl -6H O dissolved in 200 ml. of water and a liquor of 2.1 g. of Na CO and 13.0 g. of NaOH dissolved in 200 ml. of water were added dropwise in a N gas atmosphere to a four-neck flask charged with 100 m1. of Water. The addition of both liquors was controlled so that the pH of the reaction liquor was maintained above 11.0. After completion of the reaction, water was removed from the resulting suspension in a N gas atmosphere, and the residue was dried in the same atmosphere, washed with 200 ml. of water and dried at 60 C. for 15 hours in a N gas current. Results of the analysis of the product are as follows:

Composition formula Mg Ce (OH) CO -4H 0:

EXAMPLE 28 100 m1. of a rhodium chloride solution of a concentration of 0.2 mole per liter calculated as Rh O were mixed with 100 ml. of a magnesium chloride solution of a concentratino of 1.2 moles per liter calculated as MgO. The so formed mixed liquor and another mixed liquor of 25.6 ml. of a sodium carbonate solution of a concentration of 0.785 mole per liter and ml. of a potassium hydroxide solution of a concentration of 4 moles per liter were added dropwise to a 500-ml. capacity beaker charged with 80 ml. of water. The temperature was adjusted to 810 C. and the pH of the reaction liquor was maintained at 10-11. Water was rapidly removed from the resulting suspension, and the residue was washed with 200 ml. of water and dried at 60 C. for 15 hours. Results of the analysis of the product are as follows:

Composition formula Mg Rh (OH) C0 '4H O:

X ray diffraction:

EXAMPLE 29 ml. of a hydrochloric acid-acidified bismuth solution (concentration=0.2 mole/liter calculated as Bi O the pH of which has been adjusted to 1 by addition of hydrochloric acid, were mixed with 100 ml. of a solution (concentration =l.2 moles/liter calculated as MgO). Together with the so formed mixed liquor, a mixed liquor of 25.6 ml. of a Na SO solution of a concentration of 0.785 mole/liter and ml. of a caustic soda solution of a concentration of 2.0 moles/liter was added dropwise to a SOD-ml. capacity beaker charged with 50 ml. of water. The reaction was conducted at 5 C., while the pH of the reaction liquor was maintained at 11-12. After completion of the reaction, water was removed under reduced pressure, and the remaining solid was washed with 200 ml. of ice water and dried at 50 C. for 20 hours. The reaction and post-treatment were conducted in N gas atmosphere, and throughout the example ion-exchange water was used. Results of the analysis of the product are as follows:

Composition formula Mg5Bl (OH)16SO3-4H2O:

K=8.3 x/y =3 x/ (x+y) 1/ 8 X-ray diffraction:

29 EXAMPLE 30 100 ml. of a hydrochloric acid-acidified bismuth solution (concentration=0.2 mole/liter calculated as Bi O the pH of which had been adjusted to 1 by addition of hydrochloric acid, were mixed with 100 ml. of a solution (concentration-=12 moles/liter calculated as MgO). Together with the so formed mixed liquor, a mixed liquor of 25.6 ml. of a K MoO solution of a concentration of 0.785 mole/liter and 160 ml. of a caustic soda solution of a concentration of 2.0 moles/liter was added dropwise to a 500-ml. capacity beaker charged with 50 ml. of water. The reaction was conducted at 50 C., while the pH of the reaction liquor was maintained at 11-12. After completion of the reaction, water was removed under reduced pressure, and the remaining solid was washed with 200 ml. of ice water and dried at 50 C. for 20 hours. The reaction and post-treatment were conducted in N gas atmosphere and ion-exchange water was used throughout this example. Results of the analysis of the product are as follows:

Composition formula Mg Bi (OH) Mo -4H O:

EXAMPLE 31 In 200 ml. of water 8.8 g. of InCl; and 24.4 g. of MgCl -6H O were dissolved. Separately, 2.5 g. of Na SO were dissolved in 100 ml. of water. Both liquors were added dropwise to a 500-ml. capacity flask at room temperature under agitation together with an aqueous solution containing 3.0 moles per liter of NaOH while the pH of the mixture was maintained above 12.0. During the reaction air decarbonated with concentrated KOH aqueous solution was fed to the flask. In the decarbonated air the resulting suspension was filtered, and the precipitate was washed with water and dried at 80 C. for hours in the same atmosphere. Results of the analysis of the product are as follows:

Composition formula Mg In (OH) -4'H O:

EXAMPLE 32 In 200 ml. of water 8.8 g. of InCl and 16.4 g. of MgCl -6H O were dissolved. Separately, 2.9 g. of Na SO were dissolved in ml. of water. The reaction was carried out in the same manner as in Example 16 by employing the above liquors together with an aqueous solution containing 3.0 moles per liter of NaOH. Results of the analysis of the product are as follows:

Composition formula Zn In- (0H) SO -4H O:

X-ray diffraction:

d(A.) I/I 8.26 100 4.11 36 2.69 22 2.00 9 1.55 8

Chemical analysis:

MgO 29.8% (6.22) 111203 S0 11.3% (0.99) H O 26.0% (12.16)

EXAMPLE 33 In 200 ml. of water 8.8 g. of InCl and 24.4 g. of MgCl -6H O were dissolved. Separately, 3.5 g. of K HPO were dissolved in 100 ml. of water. The reaction was carried out in the same manner as in Example 17 by employing the above liquors together with an aqueous solution containing 3.0 moles per liter of NaOH. Results of the analysis of the product are as follows:

Composition formula Mg In- (OI-I) HPO -4H O:

EXAMPLE 34 In 200 ml. of water 8.8 g. of InCl and 24.4 g. of MgCl -6H O were dissolved. Separately, 7.5 g. of K Pt(CN) were dissolved in 100 ml. of water. Both solutions, together with an aqueous solution containing 3.0 moles per liter of NaOH, were reacted in the same manner as in Example 16. Results of the analysis of the product are as follows:

Composition formula Mg In (OI-I) Pt(CN) '4H O:

X- ray difiraction:

d(A.) UL, 11.94 100 5.86 28 3.83 15 2.45 10 1.58 9

Chemical analysis:

MgO 24.0% (6.21) In O 26.6% (1.0) Pt(CN) 28.4% (0.99) H O 20.9 (12.10)

31 EXAMPLE 35 8.8 g. of InCl and 24.4 g. of MgCl -6H were dissolved in 200 ml. of water, and separately, 4.7 g. of K2MOO4 were dissolved in 100 ml. of water. The reaction was conducted in the same manner as in Example 17 by employing the above two liquors and a NaOH aqueous solution of a concentration of 3.0 moles per liter. Results of the analysis of the product are as follows:

Composition formula Mg In (OH) MoO -4H O:

X-ray diffraction:

d(A.) I/I 9.60 100 4.57 62 3.04 46 2.23 25 1.56 25 Chemical analysis:

MgO 27.7% (6.22) In O 30.7% (1.0) M00... 17.5% (0.99) H O 24.1% (12.10)

EXAMPLE 36 8.8 g. on InCl and 24.4 g. of M'gC1 -6H O were dissolved in 200 m1. of water, and separately, 4.7 g. of K S O were dissolved in 100 ml. of water. The reaction was carried out in the same manner as in Example 17 by employing the above two liquors and a NaOH aqueous solution of a concentration of 3.0 moles per liter. Results of the analysis of the product are as follows:

Composition formula Mg In- (0H) S O -4H O:

X-ray diffraction:

d(A.) UL, 8.34- 100 4.13 26 2.71 10 2.11 9 1.57 5

Chemical analysis:

MgO 27.7% (6.22) In O 30.7% (1.0) S 0 17.5% (0.99) E 0 24.1% (12.10)

EXAMPLE 37 The reaction was conducted in the same manner as in Example 17 by employing a liquor of 8.8 g. of InCl and 24.4 g. of MgCl -6H O dissolved in 200 ml. of water, a liquor of 3.8 g. of K S O dissolved in 100 ml. of water, and a NaOH aqueous solution of a concentration of 3.0 moles per liter. Results of the analysis of the product are as follows:

Composition formula Mg In (OH) S O -4H O:

X-ray ditfraction:

d(A.) UL, 8.50 100 4.23 43 2.72 28 2.18 15 1.57 15 32 Chemical analysis:

MgO 29.2% (6.22) 111 0 32.4% (1.0 0 13.0% (0.99) H O 25.5% (12.12)

EXAMPLE 38 The reaction 'was conducted in the same manner as in Example 17 by employing a liquor of 8.8 g. of InCl and 24.4 g. of MgCl -6H O dissolved in 200 ml. of water, a liquor of 3.6 g. of Na CrO dissolved in ml. of water, and a NaOH aqueous solution of a concentration of 3.0 moles per liter. Results of the analysis of the product are as follows:

Composition formula Mg In (OH) CrO -4H O:

EXAMPLE 39 The reaction was conducted in the same manner as in Example 17 by employing a liquor of 8.8 g. of InCl and 24.4 g. of MgCl -6H O dissolved in 200 ml. of water, a liquor of 4.4 g. of K Se dissolved in 100 ml. of water, and a NaOH aqueous solution of a concentration of 3.0 moles per liter. Results of the analysis of the product are as follows:

Composition formula Mg In (OH) SeO -4H O:

X-ray diffraction:

d(A.) I/I 8.58 100 4.27 26 2.73 10 1.57 10 Chemical analysis:

MgO 28.2% (6.14) In O 31.3% (1.0) SeO 16.0% (0.99) H O 24.6% (12.10)

EXAMPLE 40 The reaction was conducted in the same manner as in Example 17 by employing a liquor of 8.8 g. of InCl and 24.4 g. of MgCl 6H O dissolved in 200 ml. of water, a liquor of 4.3 g. of K GeO dissolved in 200 ml. of water, and a NaOH aqueous solution of a concentration of 3.0

moles per liter. Results of the analysis of the product are as follows:

Composition formula Mg In (OH) GeO -4H O:

EXAMPLE 41 100 ml. of a hydrochloric acid-acidified bismuth solution (concentration=0.2 mole/liter calculated as Bi O the pH of which had been adjusted to 1 by addition of hydrochloric acid, and 2 g. of glycerin were mixed with 100 ml. of an aqueous solution of MgCl '6H O (concentration=0.2 mole/ liter calculated as MgO). Together with the so formed mixed liquor, a mixed liquor of 30 ml. of a sodium carbonate solution of a concentration of 0.08 mole/liter and 160 ml. of a caustic soda solution of a concentration of 2.0 moles/liter was added dropwise to a 500-ml. capacity beaker charged with 50 ml. of Water. The reaction was conducted at 5 C., While the pH of the reaction liquor was maintained at 10.5-11.5. After completion of the reaction, water was removed under reduced pressure, and the remaining solid was washed with 200 ml. of ice water and dried at 50 C. for 20 hours. Results of the analysis of the product are as follows:

EXAMPLE 42 2 g. of glycerin and 100 ml. of a bismuth solution (concentration=0.2 mole per liter calculated as Bi o the pH of which was adjusted to 1 by addition of hydrochloric acid, were mixed with 100 ml. of an aqueous solution of MgCl -6H O (concentration=0.6 mole per liter). Together with the so formed mixed liquor, a mixed liquor of 30 ml. of a sodium carbonate solution of a concentration of 0.4 mole per liter and 160 ml. of a caustic soda solution of a concentration of 2.0 moles per liter was added dropwise to a 500-ml. capacity beaker charged with 50 ml. of water. The reaction temperature was maintained at 5 C. and the pH of the reaction mixture was maintained at 10.8-12. The resulting suspension was subjected to the water-removing treatment under reduced pressure, and the residue was washed with 200 ml. of ice 34 water and dried at 50 C. for 20 hours. Results of the analysis of the product are as follows:

Composition formula Mg Bi (OH) (CO -2.5H O:

X-ray diffraction:

d(A.) I/I 7.37 3.66 50 2.52 18 2.35 10 1.54 9

Chemical analysis:

MgO 16.0% (3.00) Bi203 61.7% (1.0) C0 3.6% (0.62) H O 18.7% (7.85)

EXAMPLE 43 2 g. of glycerin and 100 ml. of a hydrochloric acidacidified bismuth solution of a concentration of 0.2 mole per liter calculated as Bi O the pH of which was adjusted to 1 by hydrochloric acid, were mixed with 100 m1. of an aqueous solution of MgCl 6H O of a concentration of 1.0 mole per liter calculated as MgO. The resulting mixed liquor and another mixed liquor of 30 ml. of a sodium carbonate solution of a concentration of 0.7 mole per liter and ml. of a caustic soda solution of a concentration of 2.0 moles per liter were added to a 500-ml. capacity beaker charged with 50 ml. of Water. The reaction was conducted at 5 C. while maintaining the pH of the reaction liquor at 11-12. Water was removed from the resulting suspension under reduced pressure, and the residue was washed with 200 ml. of ice water and dried at 50 C. for 20 hours. Results of the analysis of the product are as follows:

Composition formula Mg Bi (OI-I) (CO '3.4H O:

EXAMPLE 44 2 g. of glycerin and 100 ml. of a hydrochloric acidacidified bismuth solution of a concentration of 0.2 mole per liter, the pH of which was adjusted to 1 by addition of hydrochloric acid, were mixed with 100 ml. of an aqueous solution of magnesium sulfate of a concentration of 1.4 moles per liter calculated as MgO. The so formed mixed liquor and another mixed liquor of 30 ml. of a sodium carbonate solution of a concentration of 0.9 mole per liter and ml. of a caustic soda solution of a concentration of 2.0 moles per liter were added to a 500- ml. capacity beaker charged with 50 ml. of water. The reaction was carried out at 5 C. while maintaining the pH of the reaction liquor at 11-12. Water was removed from the resulting suspension under reduced pressure, and the residue was washed with 200 ml. of ice water and 

